Spare battery grip inserts · CR2 / CR123
One Insert for Critical Spares.
A flexible TPU 98A insert designed for compatibility with Magpul MOE and MOE+ pistol grips. It stores a spare bolt, firing pin, and two spare CR2 or CR123 batteries with the gun — not in a pocket, pack, or plate carrier. Purchase includes the insert only; bolt, firing pin, batteries, and grip are not included.
Buy — $18- Holds (not included) 1 spare bolt, 1 spare firing pin, 2 spare batteries (CR2 or CR123 model) -
- 0.45 oz — you won't feel it
- Flexible, impact-tough TPU 98A
- Compatible with Magpul MOE and MOE+ grips
- Sticks out of the grip 3/16" or 4.5mm to accommodate firing pin length
- Made by a small business in Detroit, USA
Choose your model
| 1–2 inserts | $18.00 each |
| 3–4 inserts | 5% off — $17.10 each |
| 5 or more | 8% off — $16.56 each |
| Shipping, 1–9 inserts | $10 flat (US only) |
| Shipping, 10+ inserts | FREE (US only) |
Total: $26.00
Pay with PayPal, Venmo, or credit/debit card. Card details go directly to PayPal — we never see or store them. US shipping addresses only. You'll get an email confirmation right away and a shipping email when your order goes out.
Built for the field, not the shelf
Every gun enthusiast and airsoft player, milsim regular, and outdoor sports enthusiast has been there: your optic, laser, or light dies mid-skirmish and your spares are buried three layers deep. The Detroit Prototype grip insert solves it by storing a spare bolt, firing pin, and two spare CR2 or CR123 batteries inside the hollow of your pistol grip — designed to fit Magpul MOE and MOE+ grips — the one place you'll never forget to bring.
Each insert is 3D printed from TPU 98A, a flexible engineering polymer that bends instead of cracking. It compresses to seat snugly, grips your batteries so they never rattle, and shrugs off drops, cold mornings, and rough handling that would shatter a rigid plastic holder. At just 0.45 ounces, it adds nothing to your loadout but readiness.
Pick the model that matches your gear: Insert CR2 for CR2 cells, or Insert CR123 for CR123 cells — the batteries that power most weapon lights, red dots, lasers, and rangefinders. Slide your spares in, press the insert into the grip, and forget about it until you need it.
Every insert is designed and 3D printed in Metro Detroit, Michigan by Detroit Prototype LLC, a one-person American small business — with the DETROIT PROTOTYPE logo debossed into the bottom of every unit. No imports, no middlemen, just a tool that works.
- Material
- TPU 98A (flexible)
- Capacity
- 1 bolt, 1 firing pin, 2 spare batteries
- Weight
- 0.45 oz (12.8 g)
- Fits
- Magpul MOE / MOE+ grips
- Origin
- Metro Detroit, MI, USA
- Marking
- Debossed logo, bottom
FAQ
What is included?
You'll receive the insert made of black TPU98a. NOT included: MOE grip, bolt, firing pin, batteries not included.
Is it waterproof? What's the IP rating?
The insert hasn't been formally IP tested. Based on its design, we estimate real-world protection somewhere in the IP43–IP54 range once inserted into the grip — meaning good resistance to dust and splashing water, but it is not rated for submersion. Treat it as weather-resistant, not waterproof, and dry your batteries if they get soaked.
Is Detroit Prototype affiliated with Magpul?
No. Detroit Prototype LLC is not affiliated with, endorsed by, sponsored by, or connected with Magpul Industries Corp. Magpul, MOE, and MOE+ are trademarks of their respective owner(s), used only to identify product compatibility.
Which batteries fit?
Insert CR2 holds two CR2 cells. Insert CR123 holds two CR123 (CR123A) cells. Batteries are not included.
Will it fit my grip?
The insert is designed and sized for Magpul MOE and MOE+ grips on AR-15 and airsoft platforms. The flexible TPU compresses slightly for a secure, rattle-free press fit and held in place and released by a thumb tab. Other hollow grips with similar internal dimensions may work, but MOE / MOE+ is the tested fit. Questions about your grip? Email info@detroitprototype.com.
Why TPU instead of hard plastic?
TPU 98A is a flexible, abrasion-resistant polymer. It flexes under impact instead of cracking, holds batteries with light tension so they don't rattle, and performs well in cold weather where rigid prints get brittle.
What does shipping cost?
Flat-rate US shipping: $8 for 1–3 inserts, $10 for 4–9, and free on orders of 10 or more. We ship from Metro Detroit, Michigan to US addresses only.
What's the return policy?
Returns are accepted for defective items only. If your insert arrives damaged or fails in normal use, email info@detroitprototype.com within 30 days of delivery and we'll replace or refund it.
How do payments work?
Checkout runs entirely through PayPal's secure system — pay with your PayPal balance, Venmo, or any major credit/debit card. Your card number never touches our server. Once payment clears you'll receive an order confirmation email, then a shipping notification when your order ships.
Where is it made?
Every insert is designed and 3D printed in Metro Detroit, Michigan by Detroit Prototype LLC, an American small business. The DETROIT PROTOTYPE logo is debossed on the bottom of each unit.
Field reports
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