Lump on penis mote, visible when hard, what could it be?

Please... The question seems failing to make its points clear enough for me to answer. But, "mote (more?), visible when hard..." suggests this lump is right beneath skin but obscured by lax skin of flaccid penis, but visible with stretched skin of erect penis. So, it's most likely a hyperactive sebaceous gland or tiny cyst. Such is common and needs no Rx as long as being free of symptoms.