Best Red Dot For Glock 40

HOLOSUN HS407C X2 Red 2 MOA Dot Open Reflex Sight - Durable Shake-Awake Solar Failsafe Parallax-Free Aluminum Pistol Sight for Full-Sized Handguns

HOLOSUN HS407K-X2 Compact 6MOA Dot Only Open Reflex Sight w/Shake Awake HS407K-X2

Feyachi RS-29 Reflex Sight, Red & Green Illuminated 4 Reticles Red Dot Sight Gun Sight for 20mm Picatinny Rail, 1x22x33mm

Cyelee WOLF0 Micro Reflex Red Dot Sights with Shake Awake (for RMR Pistol Cut) 3 MOA Reticle

CVLIFE Reflex Sight, 1x28x40mm Red Dot Sight, 4 Adjustable Reticles Sight for 20mm Picatinny Rail, Red Dot Optics, Absolute Co-Witness

Feyachi RS-30 Reflex Sight, Multiple Reticle System Red Dot Sight with Picatinny Rail Mount, Absolute Co-Witness

CVLIFE WolfCovert M04 Motion Awake Red Dot Sight for RMR Cut Footprint, 3MOA Shockproof Open Reflex Sight, 22x28mm Lens, Full Size optic with Adapter Plate for MOS and 21mm Picatinny Base

VOTATU PMD505-R Micro Red Dot for RMS/RMSc Footprint, Multiple Reticle Reflex Sight with Picatinny Mount - Shake Awake Optic for Pistol - 3 MOA Dot 38 MOA Circle

SIXRAY Rechargeable Red Beam and Flashlight for Pistol, 600 Lumen Tactical Pistol Light Beam Combo with Red Beam, Strobe, Magnetic Charging, Fit Picatinny

Votatu H3L-G Green Laser Sight, Aluminum Ultra Low Profile Picatinny Mount Green Dot Sight, Strobe Mode Available, Magnetic USB Rechargeable and Ambidextrous Control