The ROST MARTIN RM1S SL EXT Magazine (MPN RM10221) holds 10 rounds of 9mm Luger and is built for the ROST MARTIN RM1S pistol line, finished in black.

Key Specifications

• Holds 10 rounds of 9mm Luger.
• Built for the ROST MARTIN RM1S pistol line.
• Finished in black.
• Carries the RM1S SL EXT model designation.
• Manufactured by ROST MARTIN.
• The EXT designation marks this as a distinct factory variant from the standard SL magazine; confirm exact spec differences with us if it matters for your build.

Frequently Asked Questions

What pistol does this magazine fit? It’s built for the ROST MARTIN RM1S pistol line chambered in 9mm Luger.

What’s the difference between the SL and SL EXT versions? Both are 10-round 9mm magazines in ROST MARTIN’s RM1S line; the EXT designation marks a distinct factory variant, so confirm exact spec differences with us if it matters for your build.

Buy the ROST MARTIN RM1S Magazine

Shop it directly from ROST MARTIN, or browse the full Handgun Magazines selection at Schaefer Defense.